synthetic power-to-gas methane as fuel for...
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Synthetic Power-to-Gas Methane as
Fuel for Transportation
1
Sourc
e:
Fra
nk B
rüderli
LCM 2017: LCM for transport and mobility4 September 2017, European Convention Center Luxembourg
Sarah Wettstein and Matthias StuckiResearch Group for Life Cycle AssessmentZurich University of Applied Sciences, Institute of Natural Resource Sciences
Life Cycle Environmental Impacts of the PtG Methane Supply
Chain Powered by Renewable Electricity
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Hegemony of diesel finally crumbling?
Power-to-Gas (PtG) process uses excess power from renewable sourcesto produce hydrogen (H2). H2 is then converted to methane, which canbe used to power vehicles.
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Production of Power-to-Gas methane
13 %
NRP 70 «Energy Turnaround»: Sustainability assessment of the CO2 methanation value chain: environmental impacts and socio-economic drivers and barriersProject: Renewable Methane for Transport and Mobility (RMTM)
H2
CO2
H2 + CO2 à CH4Transport
and Mobility
Transportation and storage
Methanation
4 different vehicle types
- Petrol powered car
- Diesel powered car
- Natural gas powered car / PtG methane powered car
- Electric car
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Goal and scope of the project
49 %
13 %
Quantification of the environmental impacts of vehiclespowered by PtG methane in comparison with conventionalvehicles.
Framework- Geographic: Switzerland- Temporal: Current state of research, 2015
Functional Unit- 1 kilometre driven by passenger car (1 vehicle kilometre) based on VW Golf
2015-2016 with 110 - 130 HP
Schematic represenation and scenarios
of the production system
Blue: Scenario set electricity source Yellow: Scenario set CO2 sourceGreen: Scenario set electrolysis efficiency Orange: Infrastructure and vehicleGrey: Background data
system boundary
hydropower
electricity from photovoltaics (Poly-Si, CdTe)
electricity from incineration
plant
CO2 from waste gases (cement
industry)
H2 from alkaline electrolysis (70%
efficiency)
natural gas powered car
service station
ecoinvent database (background data)
CO2 from atmosphere
H2 from alkaline electrolysis (62%
efficiency)
Swiss grid mix
excess electricity
H2 from alkaline electrolysis (80%
efficiency)
infrastructure, electrolyser
methane
infrastructure, reactor
emissions
transport, 1 km
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Scenario electricity source: Greenhouse
gas emissions per vehicle kilometre
- 70% electrolysis efficiency- CO2 from industrial waste gases
variance, dependingon power supply for
charging battery
Error bars indicate the variance due to change in electrolysis efficiency from 70% to 62% and 80%.
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Scenario electricity source: Total
environmental impacts according to
ecological scarcity 2013
- 70% electrolysis efficiency- CO2 from industrial waste gases
variance, dependingon power supply for
charging battery
Error bars indicate the variance due to change in electrolysis efficiency from 70% to 62% and 80%.
Scenario CO2 source: Greenhouse gas
emissions per vehicle kilometre
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- Swiss electricity mix at grid for H2 production- 70% electrolysis efficiency
CO2 collection fromatmosphere causes highergreenhouse gas emissionsbut enables decentralisedmethanation!
The separation of the CO2 from atmosphere causes only minor greenhousegas emissions compared to the hydrogen production.
• Mobility fuelled by PtG methane causes lower GHGemissions per vehicle kilometre than diesel and petrolfuelled vehicles.
• Regarding GHG emissions, electrolysis efficiency has toexceed 70% in order to be competitive with conventionalnatural gas.
• Depending on the electricity source used, a reduction up to42% and 51% can be achieved according to life cycle GHGemissions and the total environmental impacts per vehiclekilometre, respectively.
• Total environmental impacts per vehicle kilometre for PtGmethane are higher compared to conventional natural gas unless excess electricity is used for methanation.
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Conclusions
Kommentar:
Stromquelle H2-Elektrolyse - für alle gelb markierten Zellen per Dropdown-Menü eine Auswahl treffen
Wirkungsgrad H2-Elektrolyse
CO2-Quelle
Stromquelle CO2-Bereitstellung
Gutschrift für Abwärmenutzung
Stromquelle Batterieladung Elektroauto
Ergebnisse für die einzelnen Prozesse (pro Kilometer)
62%
Wirkungsgra
d
70%
Wirkungsgrad
80%
Wirkungsgra
d
Fahrzeug mit
Benzinmotor
Fahrzeug mit
Dieselmotor
Erdgas-
PKW
Elektro-
PKW
62%
Wirkungsgrad
70%
Wirkungsgra
d
80%
Wirkungsgrad
Fahrzeug mit
Benzinmotor
Fahrzeug
mit
Dieselmotor
Erdgas-PKW Elektro-PKW
kg CO2-eq kg CO2-eq kg CO2-eq kg CO2-eq kg CO2-eq kg CO2-eq kg CO2-eq UBP UBP UBP UBP UBP UBP UBP
H2 Produktion 0.0126 kg 0.09 0.03 0.01 0 0 0 0 233 60 23 0 0 0 0
CO2 Produktion 0.06948 kg 0.001 0.001 0.001 0 0 0 0 3 3 3 0 0 0 0
Methanisierung 0.0336 m3 0.002 0.002 0.002 0 0 0 0 5 5 5 0 0 0 0
Verteilung 0.0336 m3 0.002 0.002 0.002 0 0 0 0 6 6 6 0 0 0 0
Treibstoffbereitstellung 1 km 0 0 0 0.04 0.02 0.02 0.03 0 0 0 70 44 20 88
Auspuffemissionen 1 km 0.000 0.000 0.000 0.16 0.15 0.068 0.000 0 0 0 83 79 33 0
Fahrzeug und Strasse 1 km 0.07 0.07 0.07 0.07 0.07 0.07 0.08 127 127 127 119 119 119 102
Gutschrift für Abwärme 1 km 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 0 0 0 0 0 0
Total 1 km 0.161 0.11 0.09 0.269 0.237 0.154 0.112 374 201 163 271 242 171 190
161 107 85 60%
Parameter 62% Wirkungsgrad 70% Wirkungsgrad 80% Wirkungsgrad
Abgase Abgase Abgase
62% 70% 80%
CH Strommix CH Strommix CH Strommix
PtG-Fahrzeug PtG-Fahrzeug ecoinvent (adaptiert)ecoinvent (adaptiert)
CH Strommix
Elektro-Auto
CH Strommix Photovoltaik CdTe Überschussstrom
Fahrzeug mit DieselmotorFahrzeug mit Benzinmotor Erdgas-Auto
Stromquelle Methanisierung CH Strommix CH Strommix CH Strommix
nein nein nein
-100
0
100
200
300
400
500
600
700
62% Wirkungsgrad 70% Wirkungsgrad 80% Wirkungsgrad Fahrzeug mitBenzinmotor
Fahrzeug mitDieselmotor
Erdgas-PKW Elektro-PKW
PtG-Fahrzeug ecoinvent (adaptiert)
Ge
sam
tum
we
ltb
ela
stu
ng
(UB
P/k
m)
Methode der ökologischen KnappheitGutschrift für Abwärme
Fahrzeug und Strasse
Auspuffemissionen
Treibstoffbereitstellung
Verteilung
Methanisierung
CO2 Produktion
H2 Produktion
0.00
0.05
0.10
0.15
0.20
0.25
0.30
62% Wirkungsgrad 70% Wirkungsgrad 80% Wirkungsgrad Fahrzeug mitBenzinmotor
Fahrzeug mitDieselmotor
Erdgas-PKW Elektro-PKW
PtG-Fahrzeug ecoinvent (adaptiert)
Tre
ibh
ausp
ote
nzi
al (
kg C
O2-e
q./
km)
TreibhauspotenzialGutschrift für Abwärme Auspuffemissionen
Treibstoffbereitstellung Verteilung
Methanisierung CO2 Produktion
H2 Produktion Fahrzeug und Strasse
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Outlook: Calculation tool
• Variable electricity source• H2 production efficiency• CO2 source• Methanation process• Credit for waste heat
• Work in progress
• Available on request, maybeonline
Sarah Wettstein and Matthias StuckiResearch Group of Life Cycle AssessmentZurich University of Applied Sciences Institute of Natural Resource Sciences Grüental, P. O. Box, CH-8820 Wädenswil
Tel.: +41 58 934 57 03 E-Mail: [email protected]: www.zhaw.ch/iunr/lca/
Questions?
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References and data sources
• Wettstein, S., & Stucki, M. (2017). Life Cycle Assessment of Renewable Methane for Mobility. Wädenswil, Switzerland: Institute of Natural Resource Sciences, Zurich University of Applied Sciences.
• Wettstein, S., & Stucki, M. (2018). Life Cycle Assessment of the CO2 Methanation Value Chain: Environmental Impacts. Wädenswil, Switzerland: Institute of Natural Resource Sciences, Zurich University of Applied Sciences
• ecoinvent Centre. (2015). Ecoinvent Data v3.2, Swiss Centre for Life Cycle Inventories. Zürich.
• Zah, R., Spielmann, M., & Ruiz, S. (2015). Analyse der Umwelt-Hotspots von Strombasierten Treibstoffen - Finaler Bericht (S. 1-68). Bern, Schweiz: Quantis, im Auftrag des Bundesamts für Umwelt (BAFU).
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• Vehicle data with real consumption, compiled by Christian Bach, EMPA
• CO2 collecting data from atmosphere, Climeworks AG, Zurich
Ecological Scarcity Method 2013
(ecopoints)